The only police department in B.C. to use a computer voice stress analyzer (CVSA) – a form of lie detection – as part of their hiring process is switching gears while there is ongoing controversy surrounding the validity of the machine and its founder.
But Saanich police say the CVSA is just an instrument for interviewers to use, and they trust in the hires they’ve made in the last decade since the machine’s been used.
“We stand by the use of this machine for the purpose of vetting potential employees,” Sgt. Dean Jantzen said. “That is an important function of our recruitment process, 100 per cent … And I can say, with all assurances, that we have uncovered criminal conduct in potential recruits, with the combined use of a skilled interviewers and this machine – and that is exactly why we have that phase in our process.”
Since last summer, the department has been planning to stop using the CVSA as part of its hiring practices. The decision based on the availability of more mainstream alternative – namely Victoria- and Vancouver-based polygraph experts.
“We’ve used it in lieu of a traditional polygraph. And it was done out of necessity at the time (in 2002 when it was first implemented),” Jantzen said. “It’s a business decision (the department) made to transition away (from the CVSA) and move towards using what is available, which wasn’t before.”
For five years, until late 2007, Saanich police also used the CVSA in criminal investigations.
“We have not used it in a homicide context, other than to verify witness statements,” Jantzen said.
He says the CVSA was not used at any point during the unsolved Lindsay Buziak case, though polygraph tests were administered the investigation.
Retired Saanich police detectives Don Wiebe and Bob Wall operate ITV Consulting, which conducts CVSAs on prospective hires for different companies, including their former employer.
Wall says a CVSA and polygraphs are two very different instruments, though both are “truth verification” devices.
“People have said they’re … the same as a polygraph, they can detect deception and lies. In reality, they can’t,” Wall said. “All it shows examiners is there’s stress related to relevant questions.”
Like Jantzen, Wall said the CVSA is only an instrument to assist the interviewer.
“The CVSA reading is absolutely meaningless without a person’s own verbal admission. The only thing that’s ever put forward to an employer is the verbal conservation with (the examiner),” Wall said.
Wall did not administer CVSAs for Saanich police while an employee there. Wiebe and Saanich officer Craig Sampson, who now heads the detective division, were trained to conduct CVSAs for the detachment.
Technology only supplements the same skills interviewers used before the devices were even available, Jantzen said.
“When I got hired (in the mid-90s), there was just interviews. And that’s the point – the skill is not in the instrument, it’s in the interviewer,” he said.
The RCMP and all other municipal forces in the province use polygraph tests when scrutinizing potential hires.
Saanich police own a CVSA device, which the department purchased in 2002 for $10,000. Though Sampson is trained on the device, it has not been used since 2007. ITV Consulting has conducted “five, six, seven pre-employments” for Saanich police since 2008, Wall said.
ITV Consulting has also conducted tests for the Oak Bay Police, B.C. Corrections and UVic security. All of which still employ the device.
• In 2006, ABC News interviewed Dr. Charles Humble, developer of the CVSA, and learned his PhD in psychology is an honorary one, granted by an unaccredited university after completing a six-hour bible studies class.
• Fewer independent studies testing the validity of voice stress analysis have been conducted, compared to the testing of a polygraph machine.
• Voice stress analysis measures frequency variations in voice that Humble says indicate deception. Some linguists argue these variations can’t be confidently attributed to deception.
• In 2002, the U.S. Department of Defense’s Polygraph Institute reported the National Research Council concluded that, when it comes to detecting deception, studies into the technology “indicated accuracy rates at or below chance levels, and low levels of reliability.”